1. Field of the Invention
The present invention relates to a control device for a motor vehicle having a cooling plate mounted between upper and lower components of a housing wherein the cooling plate includes a first printed circuit board mounted thereon. A plug component is mounted on a lower component of the housing and includes plug pins which are fitted into a second printed circuit board arranged underneath the cooling plate. The plug pins are electrically conductively connected to the first printed circuit board via conductor tracks of the second printed circuit board and connecting elements between the second and first printed circuit boards.
2. Description of the Prior Art
The document DE 41 02 265 A1 discloses a control unit whose housing is formed by a cold plate and a housing upper part. A printed circuit board, which is fitted with an electrical circuit, is arranged on the top of the cold plate, in the interior of the housing. A plug part having plug pins is arranged underneath the cold plate, fitted to it. The plug pins project through an opening in the cold plate and are passed into the printed circuit board, which is clamped over the opening, so that the plug pins and circuit are electrically conductively connected.
This control unit permits only a limited number of plug pins since the region of the printed circuit board which is intended to accommodate the plug pins, and which is arranged above the opening in the cold plate, is not available for the actual electrical circuit. In consequence, a large number of plug pins necessitate a printed circuit board having a large area and thus a control unit having large dimensions. This is disadvantageous when the installation location is a motor vehicle, with its limited space availability. If the progress in technology makes possible a smaller printed circuit board with an unchanged circuit extent and the same number of plug pins, the control unit dimensions will be reduced only slightly, however, since a relatively large region of the printed circuit board must be provided for the accommodation of the plug pins, and this region cannot be reduced in size. Furthermore, the position of the plug part with respect to the printed circuit board is fixed.
The known control unit concept is also disadvantageous from the point of view of electromagnetic compatibility since electromagnetic radiation can be emitted directly to the printed circuit board, via the plug pins, through the opening in the cold plate. Weakly and strongly radiating signal paths cannot be physically separated from one another until they are on the printed circuit board. In addition, the plug pins are passed into the central region of the printed circuit boards which results in omnidirectional radiation of electromagnetic waves to the entire circuit.